JP2685414B2 - Hollow precast concrete pillar molding apparatus and molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forming apparatus and a forming method for a hollow precast concrete column containing a reinforcing bar assembly having a medium lattice reinforcing bar.

[0002]

2. Description of the Related Art Conventionally, as this kind of molding apparatus, an inner form such as a plate is arranged in a rectangular form in a peripheral form having a U-shape in cross section, and a means for fixing the plate is used. It uses various pipes and bolts and is fixed to the peripheral formwork.

However, in the case of molding a hollow column containing a reinforcing bar assembly, in order to fix the inner formwork to the peripheral formwork,
A clamp member or the like must be passed between the cage-shaped rebar assemblies, and an inner formwork fixture such as a pipe must be attached to the space inside the rebar assembly, which is very laborious.

[0004] In particular, in a reinforcing bar assembly in which a reinforcing bar assembly is provided with a middle lattice bar crossing the internal space, the inner space is divided into a plurality of spaces by the middle lattice bar, and each space is very narrow. In addition, the work of attaching and fixing the inner mold becomes more difficult, and the work efficiency is reduced.

On the other hand, JP-A-62-233206
As described in Japanese Patent Application Laid-Open No. 4-64666 or Japanese Patent Laid-Open No. 4-64666, an elastic bag-shaped body is directly inserted by inserting the elastic bag-shaped body into the rebar assembly and inflating it by injecting air. There is a formwork.

[0006]

However, Japanese Patent Application Laid-Open No. Sho 62-62
The structure of 233206 or JP-A-4-64666 has the following problems.

(1) The elastic bag-shaped body is directly used as an inner mold, and the surface of the bag-shaped body is used as a concrete forming surface. However, the elastic bag-shaped body itself expands so as to approach a round shape. However, the concrete forming surface becomes round and it is impossible to set it in a predetermined prismatic shape. Specifically, when the bag-shaped body is inflated, the bag-shaped body bulges outward from between the column main bars and cannot be set in a predetermined prismatic shape.

(2) Moreover, since the bag-shaped body expands so as to protrude from between the column main bars as described above, a local stress is applied to the column main bar from the bag-shaped body, and the column main bar is bent. When the concrete is solidified while the column main bars are flexed in this way, the hollow column as a product cannot maintain sufficient strength at the initial design.

(3) In the structure in which the elastic bag-shaped body is inflated and its surface is directly used as a concrete forming surface to contact the concrete, the surface of the bag-shaped body is quickly damaged and can be used repeatedly. It is uneconomical.

(4) In a construction site, hollow precast concrete pillars are filled with concrete to form a solid concrete pillar together with the hollow portion. The inner surface of the hollow precast concrete column is molded into an uneven shape in order to strengthen the bond with the injected concrete. In order to form the irregularities, in the above-described conventional elastic bag-shaped body, a large number of convex portions are formed on the surface itself of the elastic bag-shaped body. However, it is very technically difficult to form irregularities on the surface of the inflatable elastic bag. For example, if a large number of projecting members are attached, they are easily peeled off when inflated, and cause deformation during inflation.

[0011]

It is an object of the present invention to simplify the structure for mounting and fixing the inner formwork, improve the work efficiency thereof, and maintain the quality of concrete columns.

[0012]

According to the first aspect of the present invention,
A plurality of column main bars arranged in parallel to each other and having a rectangular cross section,
A concrete wall is formed around a rebar assembly consisting of a plurality of hoop reinforcements that bind the column main reinforcements from the outer peripheral side and a middle lattice reinforcement that is provided so as to cross the rectangular cross-section internal space formed by the column main reinforcements. In a molding device for hollow precast concrete pillars, a peripheral formwork having a U-shaped cross-section and a plurality of plate-shaped inner formwork arranged to close each space between adjacent column main bars And a molding device for hollow precast concrete columns, which can be inserted into each of the spaces partitioned by the middle lattice bars and expands by injecting fluid to apply internal pressure to each inner formwork. .

According to a second aspect of the present invention, a plurality of column main bars arranged in parallel to each other and having a rectangular cross section, a plurality of hoop muscles for binding the column main bars from the outer peripheral side, and a rectangular cross section formed by the column main bars. In the method of forming a hollow precast concrete column that forms a concrete wall around a rebar assembly consisting of a medium lattice reinforcement that is provided so as to traverse the internal space, make sure to close this for each space between adjacent column main reinforcements. A plate-shaped inner mold is placed in the inner mold, and an inflatable bag-like body is inserted into each space defined by the grid lattice, and the bag-shaped body is expanded to remove each inner mold. To fix it, fix the above-mentioned rebar assembly in a U-shaped peripheral formwork in cross section, and pour concrete into the gap between both formwork and the upper surface of the inner formwork, Form a concrete wall around the solid A method of forming hollow precast concrete pillars, characterized by.

[0014]

[Embodiment of Forming Apparatus] FIGS. 1 and 2 show a reinforcing bar assembly 1 incorporated in a hollow concrete column according to the present invention. In FIG. 2 showing a sectional view, the reinforcing bar assemblies 1 are parallel to each other. A plurality of column main bars 2 arranged in a rectangular cross section,
It is composed of a plurality of rectangular hoop muscles 3 that bind the column main bars 2 from the outer peripheral side, and a middle lattice fiber 5 provided in the internal space of the column main bars 2 having a rectangular cross section. Pillar main line 2
Are provided at equal intervals to each other, for example, 20 are provided, and the middle lattice bar 5 is a pair of elongated rectangular-shaped vertical and horizontal reinforcing bars,
Combined in a cross shape. The cross-shaped middle grid 5 allows the cross section of the rebar assembly 1 to be divided into nine spaces S1.
... It is divided into S9.

In FIG. 1 showing the overall side view, a large number of hoop muscles 3 and center lattice muscles 5 are arranged at equal intervals in the longitudinal direction of the column main bar, and at one end of the column main bar 2, A column base screw sleeve 6 is fixed, and a small-edge formwork end plate 15 forming a part of a peripheral formwork is detachably attached to the screw sleeve 6.

FIG. 3 is a perspective view of the peripheral formwork 12 of the molding apparatus to which the invention according to claim 1 of the present application is applied, and the direction of the length of the hollow concrete column is assumed to be the front-back direction. The peripheral formwork 12 is a horizontal base board 1 that is long in the front-rear direction.
3 and a pair of left and right side plates 14 provided vertically on the base board 13 are formed in an upper open U-shape, and an edge frame end plate 15 is provided at both ends in the front-rear direction. Base board 13
Is composed of, for example, a steel frame and a plate member mounted on the frame, and the lower surface thereof is supported on the floor surface by a round shaft-shaped support member 16 extending in the front-rear direction so as to be inclined downward to the right.

The round shaft-shaped support member 16 is fixed to the floor surface, while a pair of left and right guide plates 17 are fixed to the lower surface of the base board 13, and the guide plates 17 are fixed to the shaft-shaped support member 16. It is rotatably fitted in. A leg portion 19 having the same height as the round shaft-shaped member 16 is fixed to the left end of the base board 13, while the right end portion of the base board 13 extends so as to spread rightward, and the end portion thereof is provided with a plurality of lifting jacks. Supported by 20. The right side plate 14 is reinforced by a reinforcing stay 18.

FIG. 4 is a perspective view of the inner mold 21 and the elastic bag 22 for applying internal pressure. The inner formwork 21 is divided into shapes corresponding to the spaces (total 20 places) so as to close the spaces between the main pillar rebars of the reinforcing bar assembly 1 of FIG. That is, as shown in FIG. 4, it is formed of a hard resin and is formed in a strip plate shape, and is formed so as to fit between the adjacent column main bars of FIG.

The elastic bag-like body 22 shown in FIG. 4 is provided with an expanded cross section having a size sufficiently corresponding to the cross-sectional shape of each of the spaces S1 to S9 partitioned by the center lattice streak 5 in FIG. . Each elastic bag 22 is made of rubber or the like and has an elongated shape, one end is sealed, and the other end has an air injection part 25. In this embodiment, a total of nine elastic bag-shaped bodies 22 of FIG. 4 are provided corresponding to the partitioned spaces S1 ... S9 of FIG.
Further, the bulged shape is formed to have a rectangular cross section as much as possible.

FIG. 6 shows a cross-sectional shape of the plate-shaped inner mold 21. Both end portions in the width direction of the inner mold 21 are inclined surfaces 21a so that the outer side becomes narrower, and A large number of protrusions 24 are integrally formed on the outer surface.

FIG. 5 shows an air supply mechanism for injecting air into the bag-like body 22, which comprises an air pipe 31 connected to the air compressor 30 and three branch pipes 32 branched from the air pipe 31. Each branch pipe 32 has an opening / closing valve 33 and a pressure gauge 34.
And three compressed air outlets 35 each.
Is provided. The air inlets 25 of the bag 22 are connected to the respective air outlets 35 via air hoses 37.

The connection method is, for example, three bag-like members 22 inserted into the spaces S7 to S9 in the lower part of FIG.
And the three bag-like bodies 2 inserted into the spaces S4 to S6 in the middle stage
2 and the three bag-shaped bodies 22 inserted in the upper spaces S1 to S3 are separately connected to the branch pipes 32 of FIG. That is, by operating one on-off valve 33, the upper stage,
Air can be simultaneously injected into the three bag-shaped bodies 22 in any of the middle stage and the lower stage.

[0023]

[Example of molding method] An example of a method of molding a hollow precast concrete column using the molding apparatus will be described. First, as in the following steps (1) to (9), the strip-shaped inner formwork 21 and the bag-like body 22 are attached to the rebar assembly 1 assembled in advance.

(1) The column base wood mouth form 15 of FIG. 1 is fixed to the screw sleeve 6 of the column main bar 2.

(2) In FIG. 7, the inner formwork 21 (a total of three sheets) is fitted between the column main bars 2 of the lower side spaces S7 to S9 of the reinforcing bar assembly 1 and the spaces S7 to S9.
The elastic bag-shaped body 22 corresponding to the cross-sectional shape is inserted into S9 in a deflated state.

(3) 3 inserted in the spaces S7, S8, S9
About one-third of the air is put into one bag-shaped body 22, and the four corners of each bag-shaped body 22 are aligned with the four corners of the spaces S7, S8, and S9.

(4) The inner formwork 21 is inserted between the column main bars 2 corresponding to the side surfaces of the spaces S7 and S9.

(5) Middle spaces S4, S5, as shown in FIG.
The bag-shaped body 22 is inserted into S6, and while introducing air into the bag-shaped body 22 by about 2/3, the four corners of each bag-shaped body 22 are separated into spaces S4, S.
Prepare according to the four corners of S5 and S6.

(6) The inner mold 21 is inserted between the pillar main bars corresponding to the side surfaces of the spaces S4, S6.

(7) The bag-like body 22 is inserted into the upper spaces S1, S2, S3, and while the bag-like body 22 is filled with about 2/3 of air, the four corners of each bag-like body 22 are separated into the spaces S1, S2, S3. Arrange it according to each of the four corners.

(8) A corresponding inner formwork 21 is provided between the upper columns of the spaces S1, S2, S3 and between the column main bars on the side surfaces of the spaces S1, S3.
Insert.

(9) When all the bag-shaped bodies 22 are inserted into the corresponding spaces and all the plate-shaped inner molds 21 are inserted between the corresponding column main bars, the bag-shaped bodies 22 are filled with 0. Inject air up to 9 kgf / cm ² .

(10) All inner molds 21 and bags 2
The reinforcing bar assembly 1 incorporating 2 is suspended in the peripheral formwork 12 in a horizontal state as shown in FIG.
Are fixed to the front and rear ends of the base plate 13 and the side plate 14. In this case, since the front plate 15 is already fixed to the end portion of the reinforcing bar assembly 1, the rear end plate 15 is inserted into the rear portion of the column main bar 2 and fixed to the rear surface of the base board 13 or the like.

(11) 1.2 kgf / in 9 bags 22
At the same time, air is injected up to cm ² , and each inner mold 21 is pressed from the inside and pressed against the hoop muscle 3 to be fixed. Further, in this case, since both ends in the width direction of the inner formwork 21 are inclined surfaces 21a, the inclined surfaces 21a hit the column main bars 2,
You can close the space between the main pillars.

(12) Lower the jack 20 shown in FIG.
While supporting the molding apparatus, the worker pulls out the jack 20 and tilts the peripheral formwork 12 around the round shaft-shaped support member 16 to the right downward state.

(13) In the tilted state, the bed 13
After placing concrete from the upper left side (pouring) on the top and confirming that it has turned to the right side on the bed board 13, insert the jack 20 again and raise the jack 20 to raise the peripheral formwork 12. Return to horizontal.

(14) In a state where the concrete is returned to the horizontal, concrete is poured into both side surfaces and the upper surface.

(15) Within 2.5 hours to 3.0 hours after casting, the inner mold 21 and the bag-like body 2 should be protected from impact.
Remove 2

(16) After the casting, 6.0 hours or more, a sheet or the like is put on and steam curing is performed.

(17) Finally, a hollow concrete column as shown in FIG. 9 is completed.

[0041]

According to the first and second aspects of the present invention, the following effects can be obtained. (1) A bag-like body 22 in which the inner mold 21 is inserted inside the inner mold.
Is fixed to the reinforcing bar assembly 1 by expanding
Compared to the conventional structure in which the inner formwork is fixed to the peripheral formwork with pipes, clamps, bolts, etc., the work of attaching and fixing the inner formwork is simple, and the transport and storage are also easy.

In particular, when the reinforcing bar assembly 1 is provided with the intermediate lattice bars 5, in the conventional inner frame fixing structure using a pipe or the like, bolt fastening work or the like must be performed in a very narrow space. Although the mounting and fixing work becomes very difficult, as in the present invention, the plate-like inner formwork 21 is divided so as to correspond to the space between the pillar main bars, and is divided by the intermediate lattice bars 5. When the bag-shaped body 22 is inserted into each of the spaces S1 to S9 and the inner formwork 21 is pressed and fixed by the expansion of the bag-shaped body 22, the mounting work efficiency is further improved.

(2) Since the inner mold 21 is pressed and fixed by inflating the bag-shaped body 22, the pressing force is evenly applied to the entire inner mold 21 and each inner mold 21 is stabilized. It can be pressed in the state and the quality is improved.

(3) Since the shape of the inner mold 21 is divided into a shape corresponding to the space between the pillar main bars and is inserted between the pillar main bars, it is easy to mount and position the inner mold 21.
There is no risk of slippage during the casting operation.

(4) When the concrete is solidified while the reinforcing bars are locally stressed, the reinforcing bars themselves are fixed in a bent state, and the strength at the initial design cannot be obtained. Then, since the inner formwork 21 of the plate material is interposed between the main pillars of the column, the bag itself does not have a space between the main pillars of the bar as in the case where the bag-shaped body is directly used as an inner formwork. It will not stick out from the bar and local stress will not be applied to the reinforcing bar, and the strength at the beginning of the design can be maintained,
Quality can be maintained. Of course, the inner peripheral surface of the concrete is also formed into a prismatic shape without being rounded, the thickness of the concrete peripheral wall can be formed uniformly, and the quality can be maintained also in this respect.

(5) Compared with the conventional structure in which the elastic bag-shaped body is directly used as the inner mold, the bag-shaped body 22 of the present invention does not directly use the bag-shaped body 22 as a concrete forming surface. It does not come into contact with concrete, the bag-like body 22 is less damaged, and can be used repeatedly.
It is economical.

(6) The hollow precast concrete pillar is filled with concrete in its hollow portion at an actual construction site, and this and the existing peripheral wall are integrated to form a solid concrete pillar. The unevenness for strengthening the bond between the peripheral wall of the molding and the concrete to be molded later on site may be formed in the plate-shaped inner mold, and the unevenness is directly formed on the bag-shaped body as in the conventional case. As compared with the case, the unevenness can be easily formed.

[0048]

[Other embodiments]

(1) The present invention is not limited to the reinforcing bar assembly having a cross shape as shown in FIG. 2 as the center lattice bar, but can also be applied to one having one elongated rectangular member oriented vertically or laterally. In that case, the number of bags is changed according to the section space.

[Brief description of the drawings]

FIG. 1 is a side view of a rebar assembly according to the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line II-II of FIG.

FIG. 3 is a perspective view of a peripheral formwork according to the present invention.

FIG. 4 is a perspective view of an inner mold frame and a bag-shaped body according to the present invention.

FIG. 5 is a piping diagram of an air supply mechanism connected to the bag-shaped body.

FIG. 6 is an enlarged cross-sectional view of an inner mold.

FIG. 7 is a cross-sectional view of a reinforcing bar assembly showing an inner form fitting step.

FIG. 8 is a vertical cross-sectional view of a molding apparatus showing a concrete placing step.

FIG. 9 is a vertical cross-sectional view of a hollow precast concrete column showing a state at the time of completion.

[Explanation of symbols]

 1 Reinforcing Bar Assembly 2 Column Main Bar 3 Hoop Bar 5 Middle Lattice Bar 12 Peripheral Form 21 Internal Form 22 Bag

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadamitsu Sainomoto 1-22-20 Shimanouchi, Chuo-ku, Osaka-shi, Osaka (56) References JP-A-5-16131 (JP, A) JP 62-176806 (JP, A) JP 62-233206 (JP, A) JP 4-64666 (JP, A) JP 6-155431 (JP, A)

Claims (2)

(57) [Claims] 1. A plurality of column main bars arranged in parallel with each other and having a rectangular cross section, a plurality of hoop muscles for binding the column main bars from the outer peripheral side, and a cross section rectangular internal space formed by the column main bars. A hollow precast concrete column forming device for forming a concrete wall around a reinforcing bar assembly consisting of a middle lattice bar installed in It can be inserted into each of the spaces defined by the inter-lattice muscles and a plurality of plate-shaped inner molds that are arranged to close each space between them, and each inner mold that expands due to the injection of fluid. A device for forming hollow precast concrete columns consisting of a plurality of bag-shaped bodies that apply internal pressure to the inside. 2. A plurality of column main bars arranged in parallel with each other and having a rectangular cross section, a plurality of hoop muscles that bind the column main bars from the outer peripheral side, and a cross section rectangular internal space formed by the column main bars. In the method of forming a hollow precast concrete column to form a concrete wall around the reinforcing bar assembly consisting of the middle lattice bars provided in, a plate-shaped inner mold that closes each space between adjacent column main bars While arranging the frame, insert an inflatable bag-shaped body into each space partitioned by the grid lattice, and inflate the bag-shaped body to press and fix each inner formwork to the outside. Then, fix the rebar assembly in the U-shaped peripheral formwork on the cross-sectional shape,
A method for forming a hollow precast concrete column, comprising pouring concrete into a gap between both molds and an upper surface of an upper inner mold to form a concrete wall around a rebar assembly.